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CVE Record

CVE-2026-21926: Vulnerability in the Siebel CRM Deployment product of Oracle Siebel CRM (component: Server Infrastructure).

Vulnerability in the Siebel CRM Deployment product of Oracle Siebel CRM (component: Server Infrastructure). Supported versions that are affected are 17.0-25.2. Easily exploitable vulnerability allows unauthenticated attacker with network access via TLS to compromise Siebel CRM Deployment. Successful attacks of this vulnerability can result in unauthorized ability to cause a hang or frequently repeatable crash (complete DOS) of Siebel CRM Deployment. CVSS 3.1 Base Score 7.5 (Availability impacts). CVSS Vector: (CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H).

HighCVSS 7.5Not KEV-listedUpdated
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Glexia's TakeAutomated analysishigh

Security readout for executives and security teams

Plain-English summary

CVE-2026-21926 is a high-severity availability issue in Oracle Siebel CRM Deployment. An unauthenticated attacker who can reach the affected service over TLS may cause the deployment component to hang or repeatedly crash, creating a complete denial of service. No public source provided indicates active exploitation.

Executive priority

Treat this as a business continuity risk for Siebel-dependent operations. Prioritize patch validation where Siebel CRM Deployment is internet-facing, partner-accessible, or supports critical workflows. The available evidence indicates denial of service impact, not confidentiality or integrity compromise.

Technical view

Oracle reports an easily exploitable vulnerability in Siebel CRM Deployment, Server Infrastructure component, affecting supported versions 17.0 through 25.2. The CVSS 3.1 score is 7.5 with network attack vector, low complexity, no privileges, no user interaction, and high availability impact only.

Likely exposure

Exposure is most relevant where Oracle Siebel CRM Deployment versions 17.0-25.2 are reachable over TLS from untrusted networks or business-critical internal segments.

Exploitation context

The provided sources do not show CISA KEV listing or active exploitation. The vendor description says exploitation is unauthenticated, network-accessible via TLS, and can cause hangs or repeatable crashes, not data theft or code execution.

Researcher notes

Analysis is limited to the CVE record and Oracle advisory reference. The public description does not name a CWE, root cause, exploit details, or standalone workaround. Avoid assuming broader Siebel components are affected beyond Siebel CRM Deployment Server Infrastructure.

Mitigation direction

  • Review Oracle’s January 2026 Critical Patch Update guidance for CVE-2026-21926.
  • Apply Oracle-provided updates or instructions for affected Siebel CRM Deployment versions.
  • Restrict TLS access to Siebel CRM Deployment services to trusted networks where feasible.
  • Prioritize resilience monitoring for hangs or repeated crashes until remediation is complete.

Validation and detection

  • Inventory Siebel CRM Deployment installations and confirm exact versions.
  • Flag supported versions 17.0 through 25.2 as affected.
  • Confirm whether Oracle January 2026 CPU remediation has been applied.
  • Review network paths exposing the deployment service over TLS.
  • Check operational logs and monitoring for unexplained hangs or repeated crashes.
Prepared
Confidence
high
Sources
3

Public sources used

Generated from the cited source records. This long-tail analysis has not been individually reviewed by a named human.

Potential ATT&CK relevance

Conservative CVE-to-ATT&CK context

These mappings and lookup hints may be relevant to the vulnerability behavior, CWE, affected product, or exposure path. Glexia-inferred context is not an official MITRE, ATT&CK, CWE, or CVE Program mapping.

ATT&CK lookup starting points

Use these exact CWE pages and searches to review the Glexia ATT&CK library from this CVE's weakness and description context.

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CVE-2026-21926 mapping review

Open the CVE-to-ATT&CK bridge for reviewed, inferred, or future official mappings tied to this CVE.

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Vulnerability profileCVE Program record
Severity
High
CVSS
7.5 (3.1)
Known Exploited
No
Published

Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

Official CVE source material

CNA and ADP enrichment extracted from CVE v5

These fields come from the CVE record and ADP containers, not from Glexia's Take. They preserve time-varying source decisions such as CISA SSVC, KEV status, CVSS metrics, and provider references.

1CVSS vectors
0Timeline events
0ADP providers
2Source links

CVSS vector scores

1 official score

We collect every scored CVSS vector available in the official CNA and ADP containers. When more than one version is present, the table keeps the source vectors side by side instead of collapsing them into the highest score.

ScoreVersionSeverityVectorExploitImpactSource
7.5CVSS 3.1HighCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H3.93.6Primary CVE score

Vulnerability scoring details

Base CVSS 3.1 score

7.5High
CVSS 3.1 vector shape for CVE-2026-21926Attack VectorAttack ComplexityPrivileges RequiredUser InteractionScopeConfidentiality ImpactIntegrity ImpactAvailability Impact

Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

Attack Vector
NetworkAdjacentLocalPhysical
Attack Complexity
LowHigh
Privileges Required
NoneLowHigh
User Interaction
NoneRequired
Scope
ChangedUnchanged
Confidentiality Impact
HighLowNone
Integrity Impact
HighLowNone
Availability Impact
HighLowNone

Source materials

Affected products

Products and packages named in the record

VendorProductVersion / packageStatus
Oracle CorporationSiebel CRM Deployment17.0Listed
Weakness

CWE details

No CWE listed

CWE links open Glexia weakness intelligence pages with official CWE context, developer remediation guidance, and related CVE mappings.